TAYLOR BUSER AND CINDY UNG Differential Parental Investment in Families with Both Adopted and Genetic Children

Introduction: Background Hamilton (1963): Kin selection theory means altruism correlates with shared genes Daly & Wilson (1980): Stepchildren threaten resources of genetic children to stepparent Daly & Wilson (1985, 2001): Children with stepparents are more likely to be abused

Introduction: Background Daly & Wilson (1980): Adoption occurs between kin, fitness benefits outweigh cost Callan (1985): In the West, adoption brings adaptive social benefits  Childless: “materialistic, selfish”  With children: “loving, hardworking” Contrary evidence  Hamilton et al. (2007): Adoptive households give more investment than genetic households

Introduction: Hypothesis Limitations of background research  Between vs. within Given that no genes are shared with household members  No selective drive to invest  Higher probability of negative outcomes Hypothesis: parents of at least one adopted and one genetic child bias investment toward genetic offspring

Methods – Participant Selection Adoption agency in Midwest Randomly chosen families with at least one genetic and one adopted child over 22 years old at time of study Sample sizes vary because some families had children younger than 22

Methods - Survey Children referred to by birth or adoption order Asked which investments were given and how much time was invested in each child Asked about outcomes of each child in four categories: Health, Education, Personal, and Time

Methods – Statistical Methods SPSS Controls for investment were combinations of: age, birthorder, gender, education, marital status, and parents’ income Sample sizes vary because investments did not apply to all children

Results – Adoptive Parents 126/3oo surveys returned 75.6% of respondents were women Average age: 57.6 Average spouse age: Median income: $50,000 to $74, % divorced 57.6% adopting because unable to biologically conceive children

Results – Adopted and Biological Children Average age: % Male 45.2% Adopted Adopted and genetic children didn’t differ in birthorder or gender Incomes did not differ when controlled for several factors

Results: Comparisons in investment

Differential investment in education  Preschool, tutoring, summer school Personal investments  Cars, rent, personal loans Cultural activities  Sports?  Promote intrinsic motivation  Find new skills

Outcomes of adopted and genetic children

Discussion Hypothesis is not supported, investment was not biased towards genetic children Positive investments associated with negative outcomes Most adoptees did not need any treatment or extra investment from parents Other research shows that adoptees are prone to other difficulties as well

Discussion: The “Squeaky Wheel” Summer school and private tutoring can be remedial  Same can be said for rent, treatment, public assistance Parents don’t invest more in adoptees because they are favored, but because they need more help

Discussion: Adoptees genetically predisposed? Adoptees could be genetically predisposed to negative outcomes at higher rates Alcohol and drug addiction, mental disorders are influenced by genetic factors  As are nonviolent criminality, educational performance Birthmother information rare because of confidentiality issues  One study: mothers gave up their children for adoption because of personal difficulties  Another study: birth parents gave their children up because of substance abuse, physical abuse, and mental illness

Discussion: Why adopt? Our psychology is product of strategies that paid off in the past Other cultures need optimal family size, not usual for U.S. families Adaptive: Social acceptance, “the American ideal” Maladaptive: Instinct fulfillment  Industry of child adoption very new  Takes time for a mechanism to be extinguished, maladaptive or not

Discussion: Limitations and beyoooond Limitations: Systematic ascertainment bias  Parents want to prove they don’t favor genetic children  Age children were adopted, where they were adopted from Further research:  Foster homes: If “the squeaky wheel gets the grease”, foster homes = more investment  Genetic similarity and prejudice: one white / one foreign adopted children, which one is favored?